So, another year, another iPhone. The latest version of Apple's iconic touchscreen smartphone is now available and it brings with it a whole host of new and innovative features. Is it worthy successor to its forebears the iPhone, iPhone 3G, and iPhone 3GS and, more to the point, is it worth its high asking price or should you hold out for the next round of Android, Windows 7, Meego, or WebOS devices? Read on to find out.

iPhone 4 - Video Review

iPhone 4 - Design

Most striking about the iPhone 4 is its new design. While the front is classic iPhone with its single piece of glass, single button, and symmetrical black bezel, the back has moved away from the curves of old to be replaced by a completely flat sheet of aluminosilicate-toughened glass (what do you mean you haven't heard of it?!). Combined with the new flat stainless steel sides, this gives the phone a particularly industrial, minimalist look and feel that is sure to split opinion even more than existing iPhones have.

To our minds the concept is sound and we really like the exceptional fit and finish of the phone but certainly the front bezel does now look a bit tired. In particular this seems to be because the iPhone 4 is slightly narrower and taller, yet retains the same size screen, as previous models. This makes the screen look a bit lost in the vast blackness of that bezel. It's still a pretty stunning design overall but there's definitely a prototype/engineering sample feel that takes the edge off.

By severely shrinking many of the internal components, Apple has managed to make the iPhone 4 noticeably slimmer than its forebears at just 9.3mm, and the company even touts it as the slimmest smartphone on the market. Normally we would be concerned about this as the slimmer devices get, the more difficult they tend to be to handle but thanks to its flat sides the iPhone 4 is actually pretty easy to get a good grip on. However, the pointy edges that result from all those flat surfaces make the phone feel, if not out and out uncomfortable, certainly less comfy than many rivals and even previous iPhones. Weight remains largely unchanged at 137g, 2g more than the iPhone 3GS.

Another potential pitfall of having so much glass is its propensity to crack or shatter when knocked. However, while having glass on the front and back does double your chances of this happening, it only really matters if the screen breaks, and there's just as much change of that happening on any other smartphone.

Moreover, in our experience, unlike plastic, glass screens are essentially scratch proof in normal use so using glass on the back as well will hopefully mean the iPhone 4 will look flawless for years to come, no matter how rough you treat it. Certainly we know many people that have not been overly careful yet own three year old iPhones that don't have a single scratch on the screen, which is more than can be said of the aluminium and plastic backs of said phones.

One insurmountable downside of the glass design, though, is its slipperyness. It is quite remarkable how the phone will slide off almost any surface you place it on, unless it's perfectly flat - say goodbye to resting your phone on the arm of a sofa or on your lap, unless you buy a case of course.